Conectarse a una base de datos postgres con c++

Se requiere tener instalado cpp y las librerias libpg5

sudo aptitude install libpq5 libpq-dev

Antes que nada debemos tener un servidor de base de datos postgres, login, password

Primero crea una base de datos y luego genera una tabla y algunos registros

create table people (
id              integer,
firstname       varchar(20),
lastname        varchar(20),
phonenumber     char(10)
);

insert into people (id, firstname, lastname, phonenumber) values
(1, 'Fred', 'Flintstone', '5055551234');

insert into people (id, firstname, lastname, phonenumber) values
(2, 'Wilma', 'Flintstone', '5055551234');

insert into people (id, firstname, lastname, phonenumber) values
(3, 'Barny', 'Rubble', '5055554321');

Este es el codigo c++

#include 
#include 
#include 
#include 

int     main() {
PGconn         *conn;
PGresult        *res;
int             rec_count;
int             row;
int             col;



        conn = PQconnectdb("dbname=pg_cpp_data host=localhost user=empleado password=empleado01");

        if (PQstatus(conn) == CONNECTION_BAD) {
                puts("We were unable to connect to the database");
                exit(0);
        }

        res = PQexec(conn,
                "update people set phonenumber=\'5055559999\' where id=3");

        res = PQexec(conn,
                "select lastname,firstname,phonenumber from people order by id");

        if (PQresultStatus(res) != PGRES_TUPLES_OK) {
                puts("We did not get any data!");
                exit(0);
        }

        rec_count = PQntuples(res);

        printf("We received %d records.\n", rec_count);
        puts("==========================");

        for (row=0; row
Para compilar el codigo has lo siguiente
g++ -lpq db.cpp -o db
luego ejecurta el programa y te debera salir
hernanr@eros:~/misCodigos/c++/postgresC++$ ./db

We received 3 records.

==========================

Flintstone      Fred    5055551234

Flintstone      Wilma   5055551234

Rubble  Barny   5055559999

==========================